US3999107A — Self-starting synchronous motor

Claim 1

Independent Claim 254 words

Electromagnetic motor comprising: a stator having three pole shoes, one of which being permanently magnetically biased and a divided magnetic return flux runs through the two other pole shoes; a movable element having at least two pole shoes of similar width and being magnetically interconnected to complete separate paths for said divided magnetic flux, the two poles of the movable element being spaced differently than the said three pole shoes are spaced from each other, so that in a symmetrical position of one of the shoes of the element relative to a central one of said stator pole shoes, another of the pole shoes of the element is asymmetrically positioned to each of the other two stator pole shoes, whereby a stable neutral position for the element is defined by a position of any of the pole shoes of the element opposite the biased stator pole shoe, while at least one respective other pole shoe of the movable element returns said divided flux to said two other pole shoes, so that the movable element experiences oppositely directed, balanced driving forces; and coil means including a coil on or in magnetically coupled relation with one of said other stator pole shoes to provide a flux thereto to modify said forces towards imbalance, so that the element is moved by a distance at least half a spacing between two of the poles of the movable element and towards a position in which the other one of the poles of the elements faces said biased pole shoe.

Claim 2

Dependent Claim 254 words

Electromagnetic motor comprising: a stator having three pole shoes, one of which being permanently magnetically biased and a divided magnetic return flux runs through the two other pole shoes; a movable element having at least two pole shoes of similar width and being magnetically interconnected to complete separate paths for said divided magnetic flux, the two poles of the movable element being spaced differently than the said three pole shoes are spaced from each other, so that in a symmetrical position of one of the shoes of the element relative to a central one of said stator pole shoes, another of the pole shoes of the element is asymmetrically positioned to each of the other two stator pole shoes, whereby a stable neutral position for the element is defined by a position of any of the pole shoes of the element opposite the biased stator pole shoe, while at least one respective other pole shoe of the movable element returns said divided flux to said two other pole shoes, so that the movable element experiences oppositely directed, balanced driving forces; and coil means including a coil on or in magnetically coupled relation with one of said other stator pole shoes to provide a flux thereto to modify said forces towards imbalance, so that the element is moved by a distance at least half a spacing between two of the poles of the movable element and towards a position in which the other one of the poles of the elements faces said biased pole shoe.

Claim 3

Dependent Claim 14 words

Motor as in claim 1, wherein the biased pole shoe includes a permanent magnet.

Claim 4

Dependent Claim 23 words

Motor as in claim 2 and including at least one magnetic shunt path not included in any flux path through the movable element.

Claim 5

Dependent Claim 17 words

Motor as in claim 1, wherein the biased pole shoe is centrally located between the other two.

Claim 6

Dependent Claim 12 words

Motor as in claim 4, wherein the stator is of E-shaped configuration.

Claim 7

Dependent Claim 63 words

Motor as in claim 5, wherein the width of the central pole shoe in direction of movement of the movable element is about the same as a corresponding width of the poles of the movable element, the other two poles shoes having about half that width and the edge to edge spacing to the central pole shoes is also about half that width.

Claim 8

Dependent Claim 27 words

Motor as in claim 1, wherein each of the other two pole shoes are coupled to energizing coils, including the coil on the one other pole shoe.

Claim 9

Dependent Claim 13 words

Motor as in claim 7, wherein said coils are electrically connected in series.

Claim 10

Dependent Claim 19 words

Motor as in claim 1, wherein said movable element is a rotor, the pole shoes having cylindrically curved surfaces.

Claim 11

Dependent Claim 13 words

Motor as in claim 9, wherein the rotor is a flattened cylindrical body.

Claim 12

Dependent Claim 36 words

Motor as in claim 10, said stator being one of two similarly constructed stators, which are axially offset and whose configuration has a 180° degree phase displacement, each of the stators having at least one coil.

Claim 13

Dependent Claim 39 words

Motor as in claim 1 and including means for providing pulses to the coil having duration and amplitude for accelerating the movable element by at least one half a pole center to pole center spacing of the movable element.

Claim 14

Dependent Claim 17 words

Motor as in claim 12, wherein the means include a capacitor connected in parallel to said coil.

Claim 15

Dependent Claim 18 words

Motor as in claim 13 and including a resistor serially connected to said coil and to said capacitor.

Claim 16

Dependent Claim 20 words

Motor as in claim 12, wherein the means includes a rectifier to provide one way rectified pulses to the coil.

Claim 17

Dependent Claim 12 words

Motor as in claim 12, wherein the means includes a pulse shaper.

Claim 18

Dependent Claim 19 words

Motor as in claim 1, wherein the stator poles are spaced less than the poles of the movable element.

Claim 19

Dependent Claim 17 words

Motor as in claim 1, wherein the movable element is or is part of a cipher roll.

Claim 20

Dependent Claim 109 words

An electromagnetic stepping motor, comprising: a rotor having a plurality of similarly wide and equidistantly spaced salient poles; each pole having particular width and the spacing between the poles having particular width; a stator being of E-shaped configuration with a permanently biased center pole, having a width corresponding to the width of the rotor poles, and having two outer poles spaced from the center pole at a spacing smaller than the width of the spacing between the rotor poles, and the outer poles having width smaller than the width of the center pole; and coil means on the stator for asymmetrically modifying the bias in the two outer poles.

Claim 21

Dependent Claim 109 words

An electromagnetic stepping motor, comprising: a rotor having a plurality of similarly wide and equidistantly spaced salient poles; each pole having particular width and the spacing between the poles having particular width; a stator being of E-shaped configuration with a permanently biased center pole, having a width corresponding to the width of the rotor poles, and having two outer poles spaced from the center pole at a spacing smaller than the width of the spacing between the rotor poles, and the outer poles having width smaller than the width of the center pole; and coil means on the stator for asymmetrically modifying the bias in the two outer poles.

Claim 22

Dependent Claim 35 words

A motor as in claim 19, wherein said width of the outer poles and the edge-to-edge spacing between them and the center pole together are about equal to an edge-to-edge spacing of the rotor poles.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1979-12-21	1980-06-21	1980-12-21	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1983-12-21	1984-06-21	1984-12-21	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1987-12-21	1988-06-21	1988-12-21	$7700.00	Window Closed / Lapsed

Self-starting synchronous motor

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